| Geant4 Cross Reference |
>> 1 // $Id:$
1 // -*- C++ -*- 2 // -*- C++ -*-
2 // 3 //
3 // ------------------------------------------- 4 // -----------------------------------------------------------------------
4 // HEP Random 5 // HEP Random
5 // --- engineIDulong --- 6 // --- engineIDulong ---
6 // function implementatio 7 // function implementation file
7 // ------------------------------------------- 8 // -----------------------------------------------------------------------
8 // 9 //
9 // =========================================== 10 // =======================================================================
10 // Mark Fischler - Created: Mar. 8, 2005 11 // Mark Fischler - Created: Mar. 8, 2005
11 // =========================================== 12 // =======================================================================
12 13
13 #include <string> 14 #include <string>
14 #include <vector> 15 #include <vector>
15 16
16 namespace CLHEP { 17 namespace CLHEP {
17 18
18 static std::vector<unsigned long> gen_crc_tabl 19 static std::vector<unsigned long> gen_crc_table() {
19 /* generate the table of CRC remainders for 20 /* generate the table of CRC remainders for all possible bytes */
20 static const unsigned long POLYNOMIAL = 0x04 21 static const unsigned long POLYNOMIAL = 0x04c11db7UL;
21 std::vector<unsigned long> crc_table; 22 std::vector<unsigned long> crc_table;
22 for ( unsigned long i = 0; i < 256; ++i ) 23 for ( unsigned long i = 0; i < 256; ++i ) {
23 unsigned long crc = i << 24; 24 unsigned long crc = i << 24;
24 for ( int j = 0; j < 8; j++ ) { 25 for ( int j = 0; j < 8; j++ ) {
25 if ( crc & 0x80000000UL ) { 26 if ( crc & 0x80000000UL ) {
26 crc = ( ( crc << 1 ) ^ POLYNOMIAL ) & 27 crc = ( ( crc << 1 ) ^ POLYNOMIAL ) & 0xffffffffUL;
27 } else { 28 } else {
28 crc = ( crc << 1 ) & 0xffffffffUL; 29 crc = ( crc << 1 ) & 0xffffffffUL;
29 } 30 }
30 } 31 }
31 crc_table.push_back(crc); 32 crc_table.push_back(crc);
32 } 33 }
33 return crc_table; 34 return crc_table;
34 } 35 }
35 36
36 unsigned long crc32ul(const std::string & s) { 37 unsigned long crc32ul(const std::string & s) {
37 static const std::vector<unsigned long> crc_ << 38 static std::vector<unsigned long> crc_table = gen_crc_table();
38 unsigned long crc = 0; 39 unsigned long crc = 0;
39 unsigned long end = s.length(); << 40 int end = s.length();
40 for (unsigned long j = 0; j != end; ++j) { << 41 for (int j = 0; j != end; ++j) {
41 int i = ( (int) ( crc >> 24) ^ s[j] ) & 0x 42 int i = ( (int) ( crc >> 24) ^ s[j] ) & 0xff;
42 crc = ( ( crc << 8 ) ^ crc_table[i] ) & 0x 43 crc = ( ( crc << 8 ) ^ crc_table[i] ) & 0xffffffffUL;
43 } 44 }
44 return crc; 45 return crc;
45 } 46 }
46 47
47 } // namespace CLHEP 48 } // namespace CLHEP
48 49
49 50